Abstract

Diffraction of optical electromagnetic radiation by periodic structures is of increasing importance in an expanding variety of engineering uses. Since 1930 there have been over 500 scientific papers on the subject of grating diffraction. Diffraction of electromagnetic waves by spatially periodic media may be analyzed by numerous methods and with a wide variety of possible assumptions. The most common method of analyzing grating diffraction is the coupled-wave approach, which is based on the vector electromagnetic theory and in its full rigorous form produces exact formulation without approximations. Rigorous calculations of the diffraction characteristics of various grating structures have been easily obtained. Starting with the rigorous theory and using a series of fundamental assumptions, these general theories are shown to reduce the various approximate theories [multiwave coupled-wave theory, two-wave coupled-wave theory (Kogelnik theory), optical path method, Raman-Nath theory, and amplitude transmittance theory] in the appropriate limits.

© 1991 Optical Society of America